• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.833-837
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• 2010

This study aims at finding an optimal exhaust diffuser design of a high altitude testing chamber for a low bypass turbofan engine (F404-402) with thrust pound force of 17,700 and air mass flow rate of 66kg/s ejecting at a speed of Mach 1.66. The final proposed ejector size has better pressure recovery characteristics and targets to reduce operational cost at engine performance testing. Conventional high altitude test chamber layout was adopted and first drawn in two dimensions using Autocad software so as to determine the gas path, the ejector frontal size was then determined from gas dynamics equations considering traditional gas ejection method where both the engine exhaust and cell cooling air are exhausted via the ejector. Modification to a smaller ejector with an alternative secondary cell cooling exhaust port was then performed and modelled in 3D using Solid Works software.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.824-829
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• 2016

Passenger casualties in the case of ship accidents have increased because of the increase in size and complexity of current ships (such as cruise ships). Therefore, in recent years, emergency evacuation systems are receiving increased interest so as to ensure the safety of passengers. Currently, there are only basic instructions provided, such as announcements regarding the situation, alarms, and exit signs; however, no guidance toward a proper escape route has yet been provided. To solve this problem, several emergency guiding schemes have been proposed. However, these systems ignore some of the realities of ship accidents and are impractical because various risk factors are not considered. Therefore, this paper proposes an optimal route guiding system based on an $A^*$ algorithm for emergency escape during disaster situations. This system takes into account various possible risk factors. Performance evaluation using computer simulations showed that the proposed scheme is effective and leads to safe escape routes.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.203-208
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• 2019

Medical color graphic research will serve as the basis for globally expanding and disseminating the design quality of the company's products through the era of production of medical robots. This study was based on technologies and contents suitable for the era of medical robot bed expansion, universal medical color application, ergonomic color, etc. In addition, the medical bed robot's color research direction was presented from the perspective of universal design. Accordingly, a universal color design was proposed, taking the functions of a medical robot under development by a domestic company as an example. The characteristics of this robot bed can be divided into three types of functions: first, treatment characteristics for prevention of pressure ulcers with curative, second, automatic seat exchange with cleanliness for medical environment, and third, Convenient, which can implement patient transport. The main idea is to present a combination of functional colors appropriate for this. The resulting color analysis and universal color design techniques could be a useful methodology for illustrating the appearance and function of a modern medical robot bed.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.4
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• pp.53-59
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• 2011

In this study, as a tool of evaluating biological stability of landfilled waste, influencing factors of $AT_4$ method was studied for standardizing the method. As influencing factors, initial lag time, exchanging period of $CO_2$ absorbing agent, and interval of pressure measurement were discussed, and also the relationship between content of dried food waste and $AT_4$ value were compared. Considering heterogeneity of landfilled waste and statistical error range of measurement, authors suggest that the criteria of stabilized landfill waste is $10mg\;O_2/g\;DM$ by $AT_4$ method.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.9-14
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• 2019

Currently, with the success of 5G commercialization, a server system that integrates various Internet public safety services should be developed. In this paper, we developed a public safety integrated server, which is an IoT platform connecting IoT device and IoT gateway based on IP PBX. This server is based on embedded OS and various IoT services are executed in one system and call processing / broadcasting server function that processes emergency call and emergency broadcasting in public places is built in. This system collects IoT sensor data and emergency bell information and automatically sends out emergency alarms, emergency evacuation broadcasts, etc. at an accident site in an emergency situation, and transmits the daily information to the upper IoT service server, Provide public safety management services.

• Journal of Digital Convergence
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• v.17 no.9
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• pp.399-406
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• 2019

The purpose of this study is to examine the relationship between corporate reputation and the profitability. In this study, Big Data Analysis was conducted for Hyundai Motor, Shinsegae Department Store, SK Telecom, and Amorepacific to solve research problems. The results of this study show that the effect of each corporate reputation on the profitability is different according to the company. For products such as Hyundai Motor and Amorepacific that are used directly by consumers, the corporate reputation formed by the comments was more influential. In addition, distribution Service company such as Shinsegae Department Store showed more influence by online news. On the other hand, SK Telecom did not have a significant effect on profitability. Based on the results, this study emphasizes the importance of online news and comments on corporate reputation management, and aims to contribute to establishing an efficient reputation management strategy by examining the relationship between corporate reputation and profitability.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.981-990
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• 2021

Corona 19 quarantine is often not implemented at degraded bus stops. We conducted this study to improve these problems. The inside and outside of the shelter can be sterilized with UV photocatalyst coating to maintain a hygienic and clean shelter, and passengers can breathe smoothly by reducing carbon dioxide in the shelter using CO₂ sensors and fans. It is also expected that the body temperature can be measured using a body temperature sensor to prevent more than 20% of the spread of the coronavirus in the shelter by isolating suspected coronavirus patients in the first place. When the temperature measurement distance was less than 10cm, the accuracy of the temperature measurement was 98.9%. You can communicate your intention to ride safely and clearly without contacting the bus driver by using a ride bell that uses wireless communication inside the shelter.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.34 no.1
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• pp.1-12
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• 2021

Objectives : This study was to investigate the effectiveness of thread-embedding therapy for the treatment of acute phase of Bell's palsy. Methods : Thread-embedding therapy was performed once a week on 29 patients within 1 weeks after the onset. We investigated the general characters, Yanagihara's score, House-Brackmann scale and FDI were used to evaluate the effectiveness of thread-embedding therapy. Results : Facial muscle recovery began at 13.37th day, that was about 0.36 day earlier than the previous patients who were treated without thread-embedding therapy in 2017 at the same hospital, but there was no statistical significance. In the change of each scale before and after treatment, Yanagihara's score, House-Brackmann scale, physical function and social function of FDI were changed significantly. Compared with the patients treated without thread-embedding therapy in 2017, Yanagihara's score was a little higher and House-Brackmann scale was a little lower. Conclusions : These findings suggested that thread-embedding therapy on acute phase of Bell's palsy was a little more effective than the conventional therapy without thread-embedding therapy.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.873-882
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• 2022

In this paper, we studied the voice recognition system kiosk for convenience, thinking that the kiosk widely used in modern society should compensate for the inconvenience of using by the visually impaired. Using ultrasonic sensor and PIR(Passive Infrared), it recognizes the visually impaired within the range of 80cm-40cm, introduces the kiosk through the MP3 module and induces them to come closer. Also, when the visually impaired within 40cm is recognized, the product description and order are guided through the MP3 module. A recording-based data voice recognition system and a kiosk that outputs desired items through servo motors were studied. A kiosk for the convenience of the visually impaired was manufactured through operation and optimization experiments of PIR, ultrasonic, voice recognition, and shock sensor for the manufactured voice recognition kiosk. Finally, it was confirmed that security can be strengthened by using shock sensors and emergency bells to enhance security.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.201-206
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• 2022

Energy harvesting is a concept introduced in 1954 by Bell Labs in the US while conducting research on solar cells that convert sunlight into energy. Such energy harvesting technology is a technology that collects wasted or unused energy in daily life and recycles it as electric power. In particular In the case of a photovoltaic power generation system, energy harvesting can be applied by storing electricity generated by using a battery to reduce power consumption generated by the inverter in the form of loss of power generation in cloudy weather compared to sunny days. Therefore, in this paper, energy harvesting technology is applied in the low sunlight section such as sunrise, sunset, and cloudy weather to improve the amount of power generation by recovering the power that is below the minimum operating voltage of the inverter and dissipated. Accordingly, the research contents were verified through the development of systems and algorithms according to the amount of solar power generation and the development of systems and algorithms using low power generated in sunset, sunrise, and other environments.